Reciprocating apparatus



sept. 1,l 1931. B. AMES 1,821,685

RECIPROCATING APPARATUS Filed April s. 19'29- :5 sheets-sheet 1 F4551 sep1.1, 1931. B. AMES 1,821,685

RECIPROCATING APPARATUS Filed April 3, 1929 3 Sheets-Sheet 5 E ullls. E/ n Ib v l [n1/e zor:

Z6 ,lizzie /00 Patented Sept. 1A, 1931l airain STATES PATENT OFFICE BUTLER AMES, OF LOWELL, MASSACHUSETTS RECIPROCATING PPARATS Application filed April'S, 1929. Serial No. 352,248.

' a piston which rotates about its cylindrical axis while reciprocating along a path parallel or coincident with said axis, and which functions as a valve member to control the admission and emission of fluids through suitable ports in the cylinder wall and piston itself.

An engine of this general type is illustrated in Letters Patent of the United States,

Y Nes. 1,863,547 and 1,363,548, while the same general type of apparatus is also shown in my copending application Serial No. 181,251, lil-ed May 28, 1928.

By Vway of illustration of the invention herein described, I take, for example, a motcr which, like that shown in my Patent No.

1,388,58, employs an extension portion of the piston as 'the fluid control valve member,

and accordingly, l refer the reader to'Patent No. 1,363,548 for an explanation of the vstructure'and general functional relationship of the parts ofthe motors of this type. The chief object of that invention was to secure a rotation of the piston valve member at an angular velocity in constant ratio with the angular velocity of the engine shaft; in other words, to eliminate from the rotative movement of the piston valve any decelerations and accelerations within vthe cycle of one rothereof.

In accordance with the present invention, simplified mechanism,is'provided for affording a constant ratio of angular velocity between the crank shaft and the rotary piston;

4means being providedlwhereby the piston rvalve *ir-ay be driven with the minimum of unnecessary friction, and whereby the driving means may be readily cooled and lubricated while being protected from the gases of combustion or the like.

lvfore speciiically this invention providesy a single cam factor which 1s associated W1th` a plurality of actuators, the latter being so arranged that they impart substantially constant torque to the rotary piston. To this end I prefer to arrange a sinusoidal groove within the piston skirt which is engaged by actuators that are driven by the oscillating movement of the upper end of the main' connecting rod, and also by actuators which are actuated by an auxiliary connecting rod which may be driven by al secondary throw or eccentrically disposed element of the crank shaft that causes relative movement between the upper end of this connecting rod and the piston. The various actuating factors are so arranged in relation to each other and to the cam groove that the points of maximum driving effect of one or more of the actuators occurs at the time of the minimum driving effectof'one or more of the other actuators.

In the accompanying drawings :V

Fig. 1 is a vertical section perpendicular to the axis of crank shaft rotation of a mo-Y `tor in which my invention is embodied;

Fig.v 2 is an elevational view of the piston with a yportion of theyskirt thereof broken away,'1nore clearly to show the construction thereof;

Fig. 3 is an elevational detail of the shoe or follower which is associated with the auX- iliary connecting rod Fig. 4 is a section through the piston and connecting rod assembly substantially parallel to the axis of the crank shaft, the connecting rod being shown at the upper end of its stroke in this view;

Fig. 5 is a'section on line 5-5 of Figjl, the piston Askirt being broken away along theV cam groove ;V

Fig. 6 is a sectional view of a cylinder 'showing the arrangement of the ports there- Fig. 7 is a vdiagrammatic view showing a development of the cam groove and the relative spacing of the actuators in engagement with the same;

Fig. 8 is a detail view, partly in section, ofone of the actuators;

Figs. 9 and 10 are elevational details of a portion of the piston and connecting rod assembly in various positions which they occupy during one revolution of the crank shaft;

Fig. 11 is a sectional detail of the piston,

showing an actuator engaging the cam groove and related parts;

Figs. 12 and 13 are views partly in elevation and partly in section of the main wrist pin;

Fig. 14 includes detail elevational, bottom, and vertical sectional views of the means for retaining the actuators in the cam groove;

Fig. 15 is a transverse section of the wrist' pin; and

Fig. 16 is an elevation detail of a portion of the piston.

As indicated by Fig. 1 a motor constructed in accordance with this invention may comprise a cylinder 1 having; a reciprocating andi-otating, pistonf 2 connected by a rod 3 with a crank shaft 1l. The cylinder may be provided with a re-entrant head 6 in whicliis locatedasuitable spark plugf?. An integral sleeve portion 8 of piston. 2

is receivedbetween the re-entrant head and the adjoining portion of the cylinder wall. Piston 2 is` adapted to be rotated iny relation to the cylinder andthe connectingrod,

a suitable bearing member or sliell18 being. interposedbetweentlie wrist pin26 and the pistonto permit this rotary movement.

In order to impart. a substantially uniform angular velocity to thepiston, I` provide a cam groove 30 in the piston. skirt which may be` of sinusoidalform., cooperatingactuators engagingthis: groove to rotate the piston by meansloffthe same. In the preferred` embodiment of this invention, as shown, therearev four upper and. four lower dwells in the cam groove so that each actua-- will Lrotate once.. for eachtwo' revolutions' .of the crank shaft rather thanvv once during.`

each four revolutions i of the same. The provlsion of acam grooveofthe character shown is advantageous, however, since it.

resultsv in... a. lower.` rotationalspeed of the piston, and sinceitpermits the provision of oppositely disposed ports 20 in thevsleeve' portion of the piston, and.` aL resultant pneumatic balance.4 Y

In the approved form of my invention, theshell 18 may. be arrangedto engage annular setsof balls` 22 and'22f1 which comprise thrust'bearingsbetween the upper. and` lower portions. of the shell and` annular. flanges carried by the piston. ple,numeral 19 designates the. upper'lange For examr regress which may be integral with the piston skirt, and which engages the annular series of balls 22, while the annular collar 23 may be screwed into the lower end of the piston skirt providing a race for the lower set of balls 22, or any other suitable retaining means Vmay be utilized. Preferably, as shown more particularly in Figs. 910and 11, the shell 18 may be formed of upper andlower portions which have rabbeted annular edgesfinxintertting engagement with each other, as designated by numeral 25. Tlieballl bearings may take radial thrusts and/or the outer surface of the shell may perform this function;

The main wrist pin 26 is tubular and has its ends fitting: into internal bosses 28 upon the shellQ (F ig. 5). Disposed at a suitable position ilrlelation to the wrist pin area.

pair of'vertically extendingslots 32 in the wall'` of'.y the shell' (Figs. 9 and 10). These slotsare arranged to receive and form guideways for actuator elements which reciprocate in relation to the same. The actuators 31 which engage the' cam groove may conL veniently comprise frusto-conical rollers mounted uponpins that are. carried .by reciprocatingl blocksfwhich are guidedby the sides of the slotsfSQ; these blockshave inner toothed` portions 39. which may comprise short racks engaging .segmental .toothed por tions 40 formedupon the upper endofthe connecting4 rod. Thus, angular movement of the upperend of the connectingrodeabout the wristpin axis causes a movement of these toothedzportions 40 alongdefinite arcs, and

the.vertical.reciprocation ofthe blocks 35. in theguide` slotsSQ.. Since the blocks 35 carry the actuators 3.1,.the. latterare moved along thecam. groove 30 to impart rotary movement to the piston.

Since. the actuatorslas arranged will arrive atdwell'portions ofthe cam groove at substantially` the same time, it is necessary to provide additional actuators to insure the continuous impartation of uniform torque to the rotary piston.; vfor this` purpose, I provide. a. secondary' throwv element or eccentric element 50 upon the crank shaft. which is adaptedto actuate a` secondary connecting rodl 51; As shownforexample, the lower endoffthef main' connectingrod 3 may be split, and the-cranklthrowvwhich isv engaged by thesame-may. carry an eccentric portion 50rbetweenthe bearings of the rod that engage the. crank throwrIhis eccentric has a groove 52 which is eccentric to the axis of the. crank throw;v preferably,-the axis of this groove is spacedaoutwardly from the axis `of the crank-shaft rotation atadistance somewhat greater than. is the axis of the maincrankthrow so thatl the auxiliary connectingrodl whichv is actuated thereby may have astroke which is somewhat greater than-the stroke ofthe main connecting rod;

ln order to permit the rod 51 to be actuated by the element 50, I provide an arcuate shoe 60 having a flange 63 engageable in the groove 52 andhaving a pivotal connection 64 with the lower end of the auxiliary connecting rod. Preferably, the main rod 3 may be tubular and the auxiliary rod reciprocates therein. rlhe ywrist pin 26 is hollow and its intermediate portion has openings through which the oscillating upper end of auxiliary rod 51 may extend and move. The upper portion of the wrist pin bearing of the connecting rod is similarly provided with a recess or opening 54 'to permitthe relative movement of the upper end of the auxiliary connecting rod in relation thereto. The upper end of rod 51 carries an auxiliary wrist pin having reduced end portions 7 2, one of which is shown more particularly in Fig. 8, upon which actuator rollers 31a may be rotatably mounted. lt is evident that the pin 70 may be at the upper and lower portions of its stroke in relation to the piston when the actuators 31 are in the intermediate portions of their strokes so that with the parts properly arranged, onepair of actua tors will be imparting a maximum rotational effect to the piston, While the other pair of actuators is imparting substantially no rotational eect to the same.

Fig. 5 illustrates the preferred angular arrangement of the actuators 31 and 31a in relation to the rotational axis of the piston; while Fig. 7 which may be considered in this connection illustrates the positioning ofthe various actuators in relation 'to the cam groove. Obviously, the actuators 31a are spaced at 180o from eachother since they are at opposite ends of the pin 70. Accordingly, as seen in Fig. 7, these elements may be at their mid-strokes, i. e., at the point of maximum inclination ofthe cam groove where they are imparting their maximum driving efl'ect, when the actuators 31, which preferably are located at 671/20 from the axis of the pin 4as shown in Fig. 5, are at the upper and lower dwells of the cam groove, it being evident that this arrangement permits the movement of the actuators 31 to their point of maximum effectiveness as the otherL actuators 31a arrive to the upper and lower dwell of the cam groove.`

Thus, it will be understood that the sinusoidal groove 30 ,has a maximum ordinate dimension substantially` corresponding to the path of reciprocation of both the actuators 31 and 31a, and it is further evident that the maximum rotative impulse derived from one pair of these actuators may be obtained when that pair is in the mid-portion of its path between the dwells of the cam groove, or, in other words, in position of actuators 31DL as shown in Fig. 7, while the other actuators are at a top or bottom center, for example in the position occupiedby actuators 31 in Fig. Accordingly, the aggregate effect of the rotative impulses received by the piston from the actuators, results in a ysubstantially uniform angular velocity yof f the piston, or in other words, one pair of stantially at the lower end of its path while the actuator 31a is at mid-stroke, i. e., at they portion of the cam groove which has the maxnnum inclination.

Fig. 10 shows a position of the part-s whenV the piston reaches upper dead center, the

auxiliary connecting rod 51 and the rollers 31a being at the top of their respective paths,k and the actuators 31 moving in opposite directions but being at the points of maximum inclination of the groove.

It is thus evident that the rotative impulses of one set of actuators declines as thaty of the other increases the maximum of one coincident with the minimum of the other. The aggregate torque received, therefore, from the two sets of actuators is substantially uniform. On vaccount of the momentum by the rotating piston very little restorative impulse is required to maintain its 'angular velocity of rotation while a dead Y point of either set of actuators is being passed; Consequently, there is very little friction, vibrations, or noise due to thero tation of the piston.

As shown in Fig. 6, the cylinder 1 may be provided with ports 80 and 81 in the same general manner as described in the above identiiied pistons, the ports being shaped somewhat diii'erently in accordance with the now preferred mode of valve timpairrof oppositely disposed vertical slots or grooves 104 and 105 may extend from diametrically opposed portions of the came groove 30, i. e. from opposite lower dwells thereof, an opening 97 of a diameter slightly greater than that of pin extension 72 being located in the cam groove above the vertical groove 105. Preferably the latter has a width and depth substantially the same as that of the cam groove so thata roller 31 or 31eL may be slid upwardly through groove 105 to the cam groove. The l opposite groove 104 preferably has a minimum width equal to that of pin extension 72 andis dovetailed to engage a `retainingelement 100, the depth of the groove 104 being somewhat greater than the depth of f the cam groove. An opening 96 extends through the piston skirt at the juncture of the groove 104 and the cam groove, this' opening: having a diameter equal to thev widthvot-ir the latter;

Inltli'cassemblyof a motor of this character thelo'wer halfof shell 18 may first be droppedy upon the'lconnectingfrod 3 and the tubular Wrist* pin `the'nin'serted-in the upper end ofthe'latten The upper half of shell l8rnay tlienfbe disposed-in thepisto'n. One ofthe-Blocks 'with'the roller 8l engaging theY verticalE groove `-105 nmay be slid upwardly so'thata it* engages tliegroove portion of the upper halfl of the shell'withV the roller disposediinthe cam` groove. The toothed portion of tlie'connecting rod is then engaged withA the' toothed portion 539 of the block whichhas b'eeirso disposed, andthe roller 31 upon 'that block is moved along thecam groove untilithe other block maybe slid up- Wardlyy withitsp'in portion in groove 104 so thatV it may be meshed with the opposite toothed portion of the connecting rod which is swungavayjfrom this block. The roller for theH second block may then be applied to the same through the opening 96. The

`=- lower h'alf ofsleeve I8/ is thereafter brought in'toits'peimanent relation with the upper halfth'ereo'fland the collar 23 may be secured inpl'ace to hold the parts assembled. While the secondary wrist` pin TOmay be disposed Within'the main wrist pin 26 before the parts are" thus assembled, preferably this pin is inserted' throughI the openine" 96 after the main Wrist' pin is disposed within the' pis-L ton', the rotation ofthe pin 70 in relation to `the cam groove permitting the application of al roller or rollers 31a to the same after it is located within the piston. Opening 97 which is opposite opening 96 permits pin 'to be' removed' when desired;

In' order`to prevent the movement of the actuator' rollers" out of the cam groove I provide the retaining strip 100 the edges of whichlengage the bottom of the dcvetailed groove 1041 This retaining strip is relatively thin so that its end is located outwardly of lindrical element upon the crank, a second` aryrod pivotally connected to said element, andl a cam and actuator factor between the upperend of they rod and the rotary piston,

said eccentric element being spaced outward greater distance than thecrank, whereby the `secondaryrod hasY a longer stroke thany the.

ton, anV extension of the piston providing ports, inlet andoutletopenings in the cyl'- inder wall,` and means to impart rotary movement to the piston, whereby the ports are broughty into registration with the open"- ings, said means compr-ising an eccentric ele mentA uponv the crank, a secondary rod open atively connected thereto and slidably mounted in the hollow connecting rod, and a cam'and'actuator factor between the upper end ofthe secondary rod and the rotary piston, and a second cam and actuator factor synchronized with the lirst factor.

3. Apparatus of thetype designated; comprising a cylinder, a-piston therein, a crank. a rod connecting the crank and piston, an extension of the piston providing ports,4 inlet and outlet openings iii-the cylinder wall, and means to-impart movement to the piston, where'bythe ports are br ught into registration with the openings, said means comL prising a pair oi' eccentric elements' upon the crank shaft", connecting rods actuatedby each of said elements, cam and actuator means associated with the upper ends ofv cach the crank shaft', connecting rods actuatedl with each of said throws, cam and actuator means associated with the upper ends of each' of the connecting rods andthe piston respectively, whereby relative movement between said*y iod upper ends and the piston imparts rotary movement to the latter, said actuators being arranged so that the maxi mum driving eiiect of one substantially co* incideswith the minimum offthe other.

5. Apparatus of the typedesignated, comprising a cylinder', a piston therein, a crank, a rod connecting the crank and piston, an eXtension'of the piston providing ports, inlet and outlet openings in theV cylinder wall, and means to impartrotary movement to the piston, whereby the ports are brought into registration with the openings, said means comprising a pair ot eccentric elef io ments upon the crank shaft, main and secondary ,rods actuated by said elements respectively, cam means carried by the piston and actuators associatedV withrthe upper ends of each of the connecting rods and engaging the cam means, whereby relative movement betwen saidl rod upper ends and the piston imparts rotary movement to the latter, a non-rotary shell within the piston to which the main connecting arod upper end is articulated and about which the piston rotates, a block sliding upon the shell, an actuator carried thereby and means upon the main rod upper end to slide said block and thus to cause the actuator to impart movement to the cam means.

6. Apparatus of the type designated, comprising a cylinder, a piston therein, a crank, a rod connecting the crank land piston, an extension of the piston providing ports, inlet and outlet openings inthe cylinder wall, and means to impart rotary movement to the piston, whereby the lports are brought into registration with the openings, said means comprising a pair of eccentric elements upon the crank shaft, connecting rods actuated by each of said elements, actuators associated with theupper ends of each of the connecting rods respectively, whereby relative movement between said rod upper ends and the piston may cause movement of the actuators, a common sinusoidally curved element upon the piston engaged by said actuators toreceive rotary'movement.

7. Apparatus of the type designated, comprising a cylinder, a pistontherein, a crank, a rod connecting the crank and piston, an extension of the piston providing ports, inlet and outlet openings in the cylinder wall, and means to impart rotary movement to the piston, whereby the vports are brought into registration withv the openings, e said means comprising a sinusoidally curved cam groove upon the piston skirt, and apair of actuators driven from the crank shaft, said actuatorsV being so spaced in engagement with the cam groove and so driven in synchronism as to impart substantially uniform ytorque to the piston.i I

8. Apparatus, of the type designated, comprising a` cylinder, ajpiston therein, a crank, a-hollow rod connecting the crank andpiston, the lower end o f the rod .beingsplit and having spaced bearing portions engaging the crank, an extension of the piston providing ports, inlet and outlet openings in the cylinder wall, and means to inipart rotary movement to the piston, whereby the ports are broughtinto registration `with the openings, said means comprising an eccentric element upon the crankbetween the bearings of the hollow rod, a secondary rod operatively connected to theeccentric and slidably mountedv in ,the hollow connecting rod, and a cam and'actuator factor between the upper end ofthe secondary rod andthe rotary piston, and a second cam and actuator factor synchronized with the first factor,

, 9. Apparatus of the type designated coni-" prising a cylinder, a piston therein, a crank, a tubular connecting rod between the crank and piston, a secondary rod slidably mounted in the tubular rod, an eccentric element upon the crank for oscillating the second rod, the piston skirt having a sinusoidalcam portion, a hollow wrist pin engaged by the upper end of the tubular rod,

a bearing shell engaging the ends of they wrist pin, the piston being rotatable about this shell, a secondary wrist pin secured to the secondary rod and disposed within the hollow wrist pin, and an actuator carried by said secondary pin and engaging the cani,

groove'to rotate the piston.

10. Apparatus ofv the type designated, -comprising a cylinder, a piston therein, a crank', a main rody connecting the crank and piston, an extension of the piston providing ports, inlet and youtlet openings in the cylinder wall, and means toV impart rotary movement to the piston, whereby the ports are brought into 'registration with the openings, said nieans comprising an eccentric element upon the crank, a secondary rod operatively connected thereto and a cam and actuator factor between the upper end of the secondary rod and rotary piston, said kelement having a different eccentric relation to the axis of the crankshaft than the crank, abearing shell to which the upper end of the main rod is. articulated and about ,which kthe fpistonrotates, an element movably'mounted in the shell and connected to the upper'end of the secondary rod, the relative movement between the upper ends of the vrods being effective in moving the element relative to the shell, the element carrying an actuator, and a cam surface upon the pistonA engagedy by the actuator.

. ll. Apparatus of the type designated, comprising a cylinder, a piston therein, a

crank, a rodconnecting the crank and piston, anex'tension of the piston providing ports, inlet and outletopenings in the cylinder wall, and means to impart rotary move- 4ment to the piston, whereby the ports are broughty into registration with the openings, said means comprising a sinusoidally curved camgroove upon the piston skirt, and actuators separately driven from the crank shaft said actuators being spaced and driven in synchronism continuously to impart a substantial torque to the piston. f

12. Apparatus of the type designated, comprisingy a cylinder, .a piston tlierein, a crank,y a rod connecting the crank and piston, yan extension of the piston providing ports, inlet and outletl openings in tlie-cylinf dei' wall, and means to impart rotary movement to the piston, whereby the ports kare brought into registration with the openings, said means comprising a sinusoidally 4curved cam groove upon the piston skirt, and separate pairsof actuators, saidpairsof actuators being separately driven from-theeam `crank shaft, andbeing arranged continuously to limpart torque to the piston.

13. Apparatus of the type designated, comprising a cylinder, a piston thereima crank, a rod connecting `the crank and pifsv i nient/to the piston, wherebythe portsare 'brought intoregistration with the openings, 4said means comprisinga sinusoidally curved ton, an extension of the ypistonlproviding Ap`orts, inlet and outlet openings fin' the cylin- `der wall, and means to'impartvrotaryimovement to the piston, wherebyrthe ports are brought into'registration with theopenings, saidmeans comprising a single sinusoidally curved cam ,element carried by the rpiston skirt, separately driven actuators engaging the cam element, and actuator'sbeing yand driven in synchronismcontinuously vto impart torque to the piston. 14. Apparatus "of the type designated, comprising a cylinder, a .piston therein, ,a crank, an extension of thepistomproviding ports, inlet and outletopenings in thecyllinder wall, and means` to impart `rotary movement to the piston, whereby the are brought into registration with-the `o enings, said means comprising a pair o' eccentric elements upon Ythe crankshaft, main and secondary rods @mated by @been elements respectively, cam means V'carried by `the piston, actuators associated withfthe upper ends `of ,each ofthefconnecting rods and engagingthe cam means, whereby relative movement betweemsaid rod upper ends and the piston imparts Lrotaryfmovement to the latter, a non-,rotaryfshfell `w'vithin the piston to which Ythe main connecting rod upper end isarticulated and about which the piston rotates, elements slidably mounted in the shell andcarrying a plurality vof teeth, A teeth meshed therewithand 'mounted in segmental arrangement Vfor 'movement about lthe axis yof movement of the upper end of the main rod, and actuator `'parts associated with said ,slidable .elements and engageable with the cam means'.

15. Apparatus of the type designated, comprising a cylinder, a piston" therein, ,a crank, a hollow rod connecting ,the crank and piston, the lower end of the rod being split and having spaced bearing lportions engaging the crank," an extensionlof pis- Aton providing ports, inlet and loutlet openings in'fthevcylinder wall, and means t6 impart rotary movement to the piston, Whereby the ports are -brought into'registration `with the openings, said meansI comprising an eccentric element uponthe cranklbetween vthe bearings of the hollow rod,la follower engaging the eccentric, a secondary )rod pivotally connected to the eccentric follower and' slidably mounted Vin the hollowfconnectjandactuator .factor synchronized with the 'first factor.

16. Apparatus of the type designated,

comprisingAacylinder, a piston thereina crank, a rod connecting the crankand plston,-a n 'extension of the piston providing ports,jinlet land outlet openings in thecylllnderwall, and vmeans to impart rotaryinovecamgrooveiipon the pistonl skirt, and separate pairs of actuators, said pairs or actuatorsbeing separately Adriven from the crank shaft being arranged @Qntinuously Ato import ,torquo to lille Piston, said .aot-uators "including rollers engaging ,the surfaces ,of I,the cani tgroove pinssupportlng' Said ,1,ollorS., on .opening milio plotolo ,pol-"nutons oprlioiotion 'of tblorollors to ,the .pins the lotto? aro novela-lons the oamgroovo and means Ato prevent accidental movement p, of tho rollers' out of tliisopooog- .1.7- Apparatus of tho .typo designated, oompris'ins'o oylnolor, ,o piston therein, o orolk, ,o rodoonoootos tho oreokenfl loiscvtofo, on oxtonsion of fthe ,piston ,providing ports, inlet and outletopenings inthe cylindo WolL'ond moons Kto impart lrotary lo'voloont to he piston, .whorobv tho `ports ,are brought into registration with the openlngS, Sold ,moans composing .o ,Smusoldolly A'crve'd cam groove upon the piston skirt,

and ,Sopolooo' noirs ,of ,eotuotora .Said `noirs of actuators being separately `driven lfrom ,the crank shaft/and being arranged conthinuously to impart torque vto the piston, (Seid otllotolonoluollng ,rollers engaging tlio .Surfacesof the cam ,groove andpins Isupporting said lrollershan `opening in the piston' permitting application voi the rollers the cam ,groovel and `means to prevent accidootl' movement lof the rollers ,out oflths opon'n Said meollo oomprsog o Ldoivet'ailed" ey','and akeyway orthelsame upon .to th pios" o S tho lol-ttor are moved along:

lthe outside ofthe skirt fleading toy the open- 'ing and means to Aretain the key with a por- ;tion thereof projecting into the opening. :18.,App'2lrotos of tho typo' designated,

@mol-long a minder, ay piston therein, a

crank, a rod connecting the crank and pis-- ton, an ,extension ,of `the piston `providing 'Port-s, lolot and outlet 'oponogs io tho 'oylgindfer "Wall, fand means to impart rotary movement "to the piston, whereby `the ports arefbrought into registration with the openings,'s'aid means comprising cammeans carriejd by the vpiston'and actuators associated 'with the upper end ofthe vconne'cting rod and engaging Ltheeam means, whereby rela- -tivemovementlbetween said rod yupper end ,130

and the piston imparts rotary movement to the latter, a non-rotary shell within the piston to which the connecting rod upper end is articulated and about which the piston rotates, elements slidably mounted in the shell and carrying a plurality of teeth, and teeth meshed therewith and mounted in segmental arrangement for movement about the axis of movement of the upper end of the 1l, main rod, the actuators being carried by said slidable elements and engageable with the cam means.

19. Apparatus of the type designated, comprising a cylinder, a piston therein, a crank, a rod conneoting'the crank and piston, an extension of the piston providing ports, inlet and outlet openings in the cylinder wall, and means to impart` rotary movement to the piston, whereby the ports are brought into registration with the openings, said means comprising cam means car` ried by the piston and actuators associated with the upper end of the connecting rod and engaging the cam means, whereby relative movement between said rod upper end and the piston imparts rotary movement to the latter, a non-rotary shell within the piston, a wrist pin with its ends-mounted in the shell and its mid-portion engaged by the rod, whereby the rod is articulated to the shell, the ypiston being rotatable about the latter, elements slidably mounted in the shell and carrying a plurality of teeth, teeth meshed therewith and mounted in segmental arrangement for movement about the axis of movement of the upper end of the main rod, and actuator parts associated with said slidable elements and engageable with the cam means, said shell being split with portions of the slots in each of its sections, and

means upon the pistonk for holding the sections in engagement.

Signed by me at Lowell, Massachusetts, this twentieth day of March, 1929. BUTLER AMES. 

